Adenovirus Infection

Causative agent

Adenoviruses are a group of viruses that infect the mucous membranes of humans. They commonly cause respiratory illness, and can also cause gastroenteritis, eye infection and rashes depending on the serotypes of virus. The infection can occur all year round.

Clinical features

Patients infected with adenoviruses can present with a wide range of symptoms, such as fever, respiratory symptoms (e.g. cough, runny nose, sore throat), gastrointestinal symptoms (e.g. abdominal pain, diarrhoea), and eye infection commonly known as 'red eye'. Young children, elderly and immunocompromised patients are more susceptible to this infection.

Mode of transmission

Adenoviruses mainly spread through droplets (e.g. by coughing or sneezing), direct contact with oro-nasal secretions of patients (e.g. by shaking hands), indirect contact with contaminated surfaces, or ingestion of contaminated food or water. Outbreaks of respiratory or eye infections may occur in institutional settings such as schools and hospitals.

Incubation period

The incubation period is usually 2 to 14 days.

Management

Most cases are mild and self-limited. In general, patients are given supportive treatment with adequate fluid replacement.

Prevention

1. Maintain good personal hygiene

• Wear a mask in the following situations -
  1. any persons with fever or respiratory symptoms;
  2. any persons visiting or working in high risk places such as residential care homes for the elderly, residential care homes for persons with disabilities, and clinical areas of healthcare facilities; and
  3. high risk persons (e.g. persons with underlying medical conditions or persons who are immunocompromised) visiting crowded places such as public transport.
  4. When an increasing trend in activity of respiratory viruses is expected, high risk persons are recommended to wear a surgical mask when visiting public places, while the general public should also wear a surgical mask when taking public transportations or staying at crowded places.
• Wear a mask properly, and perform hand hygiene before wearing and after removing a mask. For details on proper mask wearing, please visit CHP website at www.chp.gov.hk/files/pdf/use_mask_properly.pdf;
• Perform hand hygiene frequently, especially before touching the mouth, nose or eyes; before eating; after using the toilet; after touching public installations such as handrails or door knobs; or when hands are contaminated by respiratory secretion after coughing or sneezing.
• Wash hands with liquid soap and water, and rub for at least 20 seconds. Then rinse with water and dry with a disposable paper towel or hand dryer. If hand washing facilities are not available, or when hands are not visibly soiled, hand hygiene with 70 to 80% alcohol-based handrub is an effective alternative.
• Wear gloves and a surgical mask while disposing of or handling vomitus and faeces, and wash hands thoroughly afterwards.
• Cover your mouth and nose with tissue paper when sneezing or coughing. Dispose of soiled tissues into a lidded rubbish bin, then wash hands thoroughly.
• Avoid sharing eye medicines, eye make-up or other items that may come into contact with the eyes.
• To build up good body immunity, maintain a balanced diet, exercise regularly, have adequate rest, do not smoke and avoid alcohol consumption.
• When having respiratory symptoms, wear a surgical mask, refrain from work or school, avoid going to crowded places and seek medical advice promptly.
• Infected persons should avoid contact with children, the elderly or those with weakened immunity.

2. Maintain good environmental hygiene

• Regularly clean and disinfect frequently touched surfaces such as furniture, toys and commonly shared items with 1 in 99 diluted household bleach (mixing 10 ml of household bleach containing 5.25% sodium hypochlorite with 990 ml of water), leave for 15 – 30 minutes, then rinse with water and keep dry. For metallic surfaces, disinfect with 70% alcohol.
• Use absorbent disposable towels to wipe away obvious contaminants such as respiratory secretions, then disinfect the surface and neighbouring areas with 1 in 49 diluted household bleach (mixing 10 ml of household bleach containing 5.25% sodium hypochlorite with 490 ml of water), leave for 15 – 30 minutes, then rinse with water and keep dry. For metallic surfaces, disinfect with 70% alcohol.
• Maintain good indoor ventilation.
• Clean and disinfect eating and drinking utensils after use to reduce the risk of spread of the disease.